EPO gene expression induces the proliferation, migration and invasion of bladder cancer cells through the p21WAF1-mediated ERK1/2/NF-κB/MMP-9 pathway

Endogenous erythropoietin signaling regulates migration and laminar positioning of upper-layer neurons in the developing neocortex

Erythropoietin (EPO), the hypoxia-inducible hematopoietic hormone, has well-established neuroprotective/neurotrophic roles in the developing central nervous system and the therapeutic potential of EPO has been widely explored in clinical studies for the treatment of perinatal hypoxic brain lesion, as well as prematurity. Here, we reveal that both EPO and Epo receptor (EPOR) are expressed in the developing rat somatosensory cortex during radial migration and laminar positioning of granular and supragranular neurons. Experimental deregulation of EPO signaling using genetic approaches results in aberrant migration, as well as permanent neuronal misplacement leading to abnormal network activity and protracted sensory behavioral deficits. We identify ERK as the downstream effector of the EPO signaling pathway for neuronal migration. These findings reveal a crucial role for endogenous EPO signaling in neuronal migration, and offer important insights for understanding how the temporary deregulation of EPO could result in migration defects that lead to abnormal behavior in the adult.

Hydroxychavicol from Piper betle induces apoptosis, cell cycle arrest, and inhibits epithelial-mesenchymal transition in pancreatic cancer cells

Pancreatic cancer is a major cause of cancer-related mortality around the world. Currently, options for diagnosis and treatment are extremely limited, which culminates in a very high mortality rate. Intensive research spanning more than four decades has met several roadblocks in terms of improvement in overall survival. In this study, we have evaluated the effect of Hydroxychavicol (HC), a naturally occurring and abundantly isolatable allylarene from Piper betle leaves on pancreatic cancer cells. Our investigation reveals that HC inhibits proliferation and epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. HC induces DNA damage, as evidenced by γ-H2AX, 53BP1 induction and comet assay, which further results in mitotic catastrophe and apoptosis. The apoptosis induced by HC is JNK pathway-dependent and caspase-mediated. HC also inhibits migration and invasion of pancreatic cancer cells via a generalized repression of genes involved in EMT. A quantitative real time PCR-based array revealed at least 14 different genes to be differentially expressed upon HC treatment in pancreatic cancer cells. These results show significant potential of HC as an anticancer agent against pancreatic cancer.

Vasculogenic Mimicry Formation Is Associated with Erythropoietin Expression but Not with Erythropoietin Receptor Expression in Cervical Squamous Cell Carcinoma

Background

Vasculogenic mimicry (VM), as an endothelium-independent cancer microcirculation, has been observed in many malignancies including cervical cancer. Erythropoietin (EPO) and erythropoietin receptor (EPO-R) could produce an angiogenic effect to promote cervical squamous cell carcinoma (CSCC) progression. However, the association between VM formation and EPO/EPO-R expression in CSCC is poorly explored.

Methods

Seventy-six paraffin-embedded CSCC samples, 25 high-grade squamous intraepithelial lesion (HSIL) samples, 20 low-grade squamous intraepithelial lesion (LSIL) samples, and 20 normal cervix samples were collected. Immunohistochemistry SP method was performed to detect EPO/EPO-R expression and CD31/periodic acid-Schiff (PAS) double staining was performed to detect VM formation. The associations of EPO/EPO-R and VM with clinicopathological parameters of CSCC were analyzed. The associations between VM formation and EPO/EPO-R expression were also analyzed.

Results

The positive expression rates of EPO and EPO-R were gradually increasing along the progression of normal cervix-LSIL-HSIL-CSCC sequence (P<0.05). EPO and EPO-R expression were not significantly associated with clinicopathological parameters of CSCC patients (P>0.05). VM was significantly associated with FIGO stage, lymphovascular space involvement, and lymph node metastasis (P<0.05). VM was positively associated with EPO expression (r=0.284, P<0.05) but was not associated with EPO-R expression (P>0.05).

Conclusion

These data suggest that increased EPO/EPO-R expression may play an important role in cervical carcinogenesis. EPO overexpression may promote VM formation in CSCC.

Nodal regulates bladder cancer cell migration and invasion via the ALK/Smad signaling pathway

Background

Bladder cancer is the most common malignant tumor of the urinary tract. We aimed to explore the biological role and molecular mechanism of Nodal in bladder cancer.

Materials and methods

The expression of Nodal in bladder cancer tissues and cells was determined by quantitative real-time polymerase chain reaction. The effect of silencing of Nodal on cell proliferation, clone formation, and migration and invasion was evaluated by MTT cell proliferation assay, colony formation, and transwell assays, respectively. Western blot analysis was employed to detect the expression of proliferation- and invasion-related proteins and proteins involved in ALK/Smad signaling.

Results

We found that the expression of Nodal was significantly increased in bladder cancer tissues and cell lines. Downregulation of Nodal effectively weakened cell proliferation, clone formation, and cell migration and invasion abilities. The protein expression levels of CDC6, E-cadherin, MMP-2, and MMP-9 were also altered by downregulation of Nodal. Knockdown of Nodal also blocked the expression of ALK4, ALK7, Smad2, and Smad4, which are involved in ALK/Smad signaling. Additionally, the ALK4/7 receptor blocker SB431542 reversed the promotive effects of Nodal overexpression on bladder cancer cell proliferation, migration, and invasion.

Conclusion

Our study indicated that Nodal functions as an oncogene by regulating cell proliferation, migration, and invasion in bladder cancer via the ALK/Smad signaling pathway, thereby providing novel insights into its role in bladder cancer treatment.

Erythropoietin Induces an Epithelial to Mesenchymal Transition-Like Process in Mammary Epithelial Cells MCF10A

Anemia is associated with chemotherapy treatment in cancer patients. Erythropoietin (EPO) has been used to treat anemia of cancer patients, because it stimulates erythropoiesis. However, treatment of breast cancer patients with EPO has been associated with poor prognosis and decrease of survival. Epithelial to mesenchymal transition (EMT) is a process by which epithelial cells are transdifferentiated to a mesenchymal state. It has been implicated in tumor progression, because epithelial cells acquire the capacity to execute the multiple steps of invasion/metastasis process. However, the role of EPO on EMT process in human mammary epithelial cells has not been studied. In the present study, we demonstrate that EPO promotes a decrease of E-cadherin expression, an increase of N-cadherin, vimentin, and Snail2 expression, activation of FAK and Src kinases and an increase of MMP-2 and MMP-9 secretions. Moreover, EPO induces an increase of NFκB DNA binding activity, an increase of binding of p50 and p65 NFκB subunits to Snail1 promoter, migration, and invasion in mammary non-tumorigenic epithelial cells MCF10A. In summary, these findings demonstrate, for the first time, that EPO induces an EMT-like process in mammary non-tumorigenic epithelial cells. J. Cell. Biochem. 118: 2983-2992, 2017. © 2017 Wiley Periodicals, Inc.

Low expression of TMEM67 is a critical predictor of poor prognosis in human urothelial carcinoma of the bladder

OBJECTIVES

The aim of the study was to evaluate the expression of TMEM67 in urothelial carcinoma of the bladder (UCB) tissues and to determine the potential relevance between the expression of TMEM67 and prognosis of UCB.

MATERIAL AND METHODS

In this study, the expression of TMEM67 mRNA was performed by quantitative real-time PCR in 80 UCB and 54 noncancerous tissues. The expression of TMEM67 protein was identified by immunohistochemistry and western blotting. Chi-square test was conducted to verify the relevance between the expression of TMEM67 and clinical parameters. Kaplan-Meier survival analysis was demonstrated between high or low expression level of TMEM67 mRNA and recurrence-free survival probability. Cox regression analysis was conducted to evaluate the relevance between the expression of TMEM67 and the prognosis in UCB.

RESULTS

Low expression of TMEM67 mRNA and protein was detected in most of UCB tissues using quantitative real-time polymerase chain reaction and western blotting, compared with noncancerous tissues. Low expressions of TMEM67 were associated with TNM stage, grade, and lymph node metastasis (P<0.05). Kaplan-Meier analysis showed that the low expression of TMEM67 mRNA had significantly shorter recurrence-free survival probability (P = 0.018). Cox regression analysis confirmed that low expression of TMEM67 mRNA predicted poor prognosis of patients with UCB (HR = 2.950, P = 0.029, 95% CI: 1.116-7.796).

CONCLUSIONS

TMEM67 expression is low in UCB tissues, and the TMEM67 low expression predicted poor prognosis of patients with UCB.

Mangiferin regulates proliferation and apoptosis in glioma cells by induction of microRNA-15b and inhibition of MMP-9 expression

Mangiferin, a flavonoid extracted from the leaves of the Anacardiaceae plant, the mango tree, has physiological activity and pharmacological effects in many aspects. The present study aimed to clarify the effect of mangiferin on proliferation and apoptosis of glioma cells and the mechanism of these curative effects of mangiferin. In this experiment, we detected the proliferation using 3-(4,5-dimethylthylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. Then, cell apoptosis of U87 glioma cells was measured with the Annexin V-FITC/propidium iodide (PI) apoptosis detection kit, DAPI staining assay and the caspase-3 and caspase-9 activity assay kit. Next, quantitative real-time PCR and gelatin zymography were used to analyze the expression of microRNA-15b (miR-15b) and matrix metalloproteinase-9 (MMP-9), respectively. MMP-9 agonist, miR-15b mimics and anti-miR-15b mimics were added to the U87 glioma cells for elucidating the mechanisms involved in the curative effects of mangiferin. In the present study, mangiferin notably restrained the proliferation and increased the apoptosis of the U87 glioma cells. Meanwhile, mangiferin specifically promoted the expression of miR-15b and suppressed the level of MMP-9 in the U87 glioma cells. miR-15b regulated the expression of MMP-9 in the U87 glioma cells. MMP-9 agonist and anti-miR‑15b reduced the curative effects of mangiferin in the U87 glioma cells. In summary, mangiferin regulates proliferation and apoptosis in glioma cells by induction of miR-15b and inhibition of MMP-9 expression.

U0126 protects cells against oxidative stress independent of its function as a MEK inhibitor

U0126 is a potent and selective inhibitor of MEK1 and MEK2 kinases. It has been widely used as an inhibitor for the Ras/Raf/MEK/ERK signaling pathway with over 5000 references on the NCBI PubMed database. In particular, U0126 has been used in a number of studies to show that inhibition of the Raf/MEK/ERK pathway protects neuronal cells against oxidative stress. Here, we report that U0126 can function as an antioxidant that protects PC12 cells against a number of different oxidative-stress inducers. This protective effect of U0126 is independent of its function as a MEK inhibitor, as several other MEK inhibitors failed to show similar protective effects. U0126 reduces reactive oxygen species (ROS) in cells. We further demonstrate that U0126 is a direct ROS scavenger in vitro, and the oxidation products of U0126 exhibit fluorescence. Our finding that U0126 is a strong antioxidant signals caution for its future usage as a MEK inhibitor and for interpreting some previous results.